Ultra high frequency electron discharge device



March 29, 1949. J, GLAUBER 2,465,370

' ULTRA HIGH FREQUENCY ELECTRON DISCHARGE DEVICE Filed June 26, 1944 2 Sheets-Sheet l I N V EN TOR. ao/r/v J. 6140552 March29, 1949.. 1 .1. J. GLAl J BER 2,465,370

ULTRA HIGH FREQUENCY ELECTRON DISCHARGE DEVICE Filed June 26, 1944 '2 Sheets-Sheet 2 'IIIIIIJIIIIIII INVENTOR. JOHN J. amuse/e ATTORNEY Patented Mar. 29, 1949 ULTRA HIGH FREQUENCY ELECTRON DISOHARGE DEVICE John J. Glauber, .West Orange, N.J.,.assi gnorto Federal Telephone and Radio Corporation, New York, N. Y a oorporation of Delaware Application June 26, 1944, Serial.No.- 542,089

.19 Claims.

This inventionrelates to an assembly for an electron discharge device and has particular applicability to ultra-highfrequency devices.

An object of the present invention is the pro vision of an improved assembly for an electron discharge device particularly an assembly for use in ultra-high frequencyapplications.

Another object of the present invention is the provision of such an assembly in which theelectrodes are accurately spaced and in which'such accurate spacing is readily accomplished during assembly.

Another object of the present invention is the provision of a novel cathodeconnection. One feature of this connection is the fact that not only is it of relatively low impedance, but it is also of relatively low thermal conductivity, thus preventing dissipation of the energy supplied-to the cathode. Another feature of this connection is the use of the cathode and grid mount to provide such connection.

Some of the other features of this invention include an assembly characterized by simplicity, ease of assembly, sturdiness, and tolerance for heat expansion and contraction.

Other and further objects, features, and advantages of the present invention will become apparent, and the foregoing will be best understood, from the following description of an embodiment thereof, reference being had to the drawings, in which:

Fig. 1 is a sectional view of an assembly for an electron discharge device embodying my invention; and

Figs. 2, 3 and 4 are sections taken substantially along the lines 2-2, 3-3, and 3-4, respectively, of Fig. 1, but in case of Figs. 2 and 3 certain central elements which would appear in section have been omitted or shown in plan for clarity. See elements 22.

Referring now to the drawings and particularly Fig. 1, the numeral 1 generally designates the assembly which includes an envelope generally indicated at 2, said envelope 2 including insulating portions 3, 4 and 5. Envelope 2 is closed at its lower end by a preformed header 6 of insulating material, and closed atits upper end by a conductive disc I which includes a depressed or dished-in portion 8 at the center thereof comprising a substantially conical Wall 9 and a flat circular bottom portion iii. Conductive discs H and i2 extend through the envelope between insulating portions 3 and 4,

and 4-and 5, respectively, and are. hermetically sealed to said portions tothereby completeihe envelope.

The insulating portions of the envelopeare preferably made ofa heat resistant material and the conductive discshll and Here preferably made of someknown conductivematerial :having the same coefiicient of expansion as,the ;1 sulating portions.

.In the assemblyillustrated in the drawings, three electrodes areemployed, comprisin an anode it, a cathode l.4,.and a gridifi interposed between the anode and cathode. .Theanodeis supported and electrically connected to the inner side of the bottomportionlll of disc I byany suitable method such a's,.for example, by welding.

The cathode Hi and the grid l5 are supported on a mount it ,at an accurate distance from said anode,,said mount. beinginserted intothe assembly before theiheader 6 is secured to the insulating portion5.

The mount 16 includes ac'onductiveportion ll. As viewedincross-section (see Figl) this conductive portion i7 is comprised of a, fi,at.top l8, diverging walls l9.andvertical walls ,zoeepending from thelower endsof thedivelging walls IS. .A pair of aprons 2i, isee Fig. 4.), 2 2a formed at opposite endsofsaid, conductiveportion li. Saidportion l! maybedrawnjroma single piece of,fmeta1,,by,the useof asuitable. die, or may be formed ,of ,separate sheetsof metal welded togetherorbylany othersuitable method.

The mount also includestwo insulating members 22 whichmay' be made of micahand consist of thin, substantially rectangularplates, .vertically arranged on opposite ends of theconductive portion I], ach abutting, oneof the ,apronsjl and secured ,to said apron by any suitable means such as, for example eyelets 23. Thecj-topsj i ofv said insulating members '22 extends substantial distanceabove thetop N3 of the. conductive portion IT. ,A horizontal opening 25 is provided in each ofsaid insulating. membrS. Z2

a short distance. above the top, 18 of the ,conduc- 3 a predetermined accurate distance above the cathode I4.

To assure accurate spacing between the grid, cathode and the anode, a predetermined exact rectangular portion of the top corners of the insulating members 22 are cut away to thereby form positioninglshoulders 29 adjacent positioning ends 30 on top of each of said insulating members 22. In arranging the mount iii in the assembly, the mount is inserted through a relatively large opening 3| in disc l2. The disc II is provided with a rectangular but smaller opening 32 through which the top 24 of the insulating members 22 projects. The opening 32 is too small, however, to permit shoulders 29 to pass through said opening, and said shoulders engage the bottom portions of said disc ll adjacent said opening, thereby determining how far the mount can be inserted upward into the assembly. In forming the envelope 2, disc II is spaced from disc 1 by a predetermined accurate distance. This may be accomplished by using a suitable fixture or jig. Therefore since disc II is accurately spaced from disc 1 and since mount l'6 is accurately spaced in relation to disc II, the anode l3 on disc 1 will consequently be accurately spaced from the cathode and grid which are in turn accurately arranged on mount it. To insure further that the grid and cathode will be aligned directly underneath the anode, and to prevent horizontal displacement from this position, the upper portion of the insulating members, that is, the portion within the opening 32, registers with portions of disc I I defining said opening, and the mount is thereby positioned horizontally.

To secure the mount in the aforedescribed accurately determined position, L-shaped flanges 33 are provided at the bottom of disc l2 immediately adjacent opening 3| and the vertical walls 20 are welded to the depending portion of said flanges 33 after the mount is in said position.

Discs 1, II and I2 provide external terminals which are connected inside the tube to anode l3, grid 15 and cathode [4 respectively. These discs are of relatively low impedance. Anode I3 is directly mounted on the reentrant bottom portion I'O of disc I and electrically connected thereto. Grid I5 is electrically connected to disc II by means such as a pair of preformed springs 34,

each of which is mounted on one of the insu lating members 22 by any suitable means such as, for example, pins 35. One of the pins 35 on each of the insulating members 22 is connected by means of a metallic strap 36 to one of the longitudinal supports supporting the transverse rid wires. When the mount I6 is inserted into the assembly, the ends 31 of springs 34 contact the bottom of disc II. If desired, the ends 31 may be thereafter welded to the disc II. This is accomplished before the header 6 is sealed to insulating portion 5 and for this purpose the large opening 3| in disc I2 is preferably subgrid and cathode; alternating current of intermediate frequencies, usually the modulation frequencies, and higher frequency currents flow to the cathode. Therefore the connection to the cathode must carry direct current, intermediate frequencies and higher frequencies. The connection should offer low resistance to the D. C. currents and also have low impedance for the intermediate and higher frequencies. At the same time, in order to prevent dissipation of the heat of the cathode, this connection should have relatively low thermal conductivity. The foregoing is accomplished in the following manner in accordance with my invention.

The disc I2 is electrically connected with the conductive portion ll of the mount I6. The conductive portion I1 is of low inductance, low impedance to both the intermediate and higher frequencies, and low resistance to direct current. The fiat top l8 of the conductive portion I1 is arranged close to and parallel with the undersurface of the cathode l4, thereby providing a substantial capacity therebetween forming a low impedance connection for the higher frequency currents. This connection is obviously of low thermal conductivity since the cathode and said fiat top I8 are spaced apart. In addition to this low impedance connection, a galvanic connection is provided between the conductive portion ll of the mount and the cathode M. This galvanic connection may be made by providing a pair of downwardly-projecting cars 38 on the cathode towards opposite ends thereof, which ears 38 lie adjacent similar ears 39 struck out of the flat top I8 of the conductive portion ll of the mount. Ears 38 and 39 are connected together to thereby provide the galvanic connection. It is important that the cross-sectional area of the ears be small so that the connection will be of relatively low thermal conductivity and relatively little heat will be transferred thereby from the cathode to the mount. The intermediate frequencies will tend to divide themselves between the aforementioned galvanic connection and the low impedance connection, and the dimensions of said connections should be proportioned so that low impedance is offered to the intermediate currents flowing to the cathode.

In regard to the cathode I 4. only the upper surface thereof facing the anode I3 through grid wires 26 is coated with an emissive coating as indicated by numeral 40, Fig. 3. A heater element 4| is inserted within the cathode after it has been arranged on the mount. and lead wires 42 are connected to opposite ends of said heater element. The lead wires 42 are connected. for example. by welding, to the inner ends of contact pins 43 which are sealed through the header 6. This welding is accomplished before the header 6 is sealed to the insu ating portion 5. The header 6 is held a sufilcient distance awav from the insulating portion 5 to allow a welding tool to be inserted therebetween and the lead wires 42 are made long enough to reach the inner ends of pins 43 while the header is maintained at this distance from said insulating portion 5. After the welds have been made. the welding tool is removed and the header is then moved up to and sealed to the insulating portion 5. The lead wires 42 bend and take the shape indicated in Fig. 1. To control the bending of the lead wires 42, each of said wires is welded to a central eyelet 44 fastened to one of the insulating members 22. A portion of each of the aprons 2| is cut away arounditheeyelet so thattheeyeletsl l andthe lead wires 42 which are-attached to said eyelets are electrically insulated from the conductive portion of the mount.

A gettering element 45 may be connectedbev tween one of thecontactwpinsltand a-similar contact pin Mi sealed through the header. The assembly may be provided with the usual exhaust tip 41 through which it is evacuated. Other details o-fthe assembly will be apparentfromthe foregoing description to those versed in: the art.

it will be seen that this assembly :allows for expansion and contractionof the variousportion's such as, for example, the discs, without injury to the assembly. For example. it disc I! expands the vertical walls of the mount IG- aresuificientlyfiexible to give, without: causing distor-- tion of the mount. Likewise if .disc H expands, there is sufiicient flexibility in the insulating members 22, particularly'if they are made 'of' mica, to allow for this expansion.

While, the above description has been that of a .triode, it will be obvious that my invention is also applicable toelectrode, discharge, devices having adifferent number of electrodes. Other variations in theabove-described.structure may be made without departing from theteachings or nay-invention. Accordingly, while I have described above the principles of my invention in connection with a specific device, it-is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of my invention. as set. forthin the objects and the claims.-

I claim: a

l. An. electron discharge device comprising. an envelope, an electrode mounted on a portion of and located within the envelope, at member mounted through the envelope and at a distance from said electrode fixed bythe dimension of the envelope portion extending between said electrode and said member, amount arranged adjacentsaid member, a second electrode supported on said mount,.means on said mount providing with said memberaccurate spacing of said electrodes from each other, and means fixingsaid mount in position within the envelope .tomaintain said accurate spacing V 2. An electron. discharge device comprising an electrode in said device, a member having, an opening therein and mounted at afixed distance from said electrode, a mount arranged adjacent said member inside said envelope, a secondelectrode supported on said mount including a portion projecting into and registering with portions of said member and having means engaging said member and thus accurately spacing said electrodes from each other, and means fixing said mount in a given position to maintain said accurate spacing.

3. An electron discharge device according to claim 2', wherein the portions of the walls are those definin said opening, and the means of the mount engaging said member comprises shoulders engaging portions of said member ad- .iac'ent' said opening.

4., An electron discharge device-comprisingan envelope, a pair of members defining portions of said envelope, one: member" extending through said envelope with. an envelope portion between said members, said members being spaced'apart a distance fixed by the dimensions of said envelope portion, an electrode mounted on one of said members, a mount, a second electrode supported on said mount, means on said mount providing with theother of said members accurate spacing of the electrodes in relation to each other, and

.means fixing said mount in position within said envelope to maintain said accurate spacing.

5. An electron discharge device comprising an envelope, a pair of members extending through said envelope and separated a fixed distance by a portion of said envelope, an electrode mounted on one of, said members, a mount, a second electrode supported on said mount, means on said'mount providing with'the'otherof said members accurate spacing for said electrodes in relation to each other, and means fixingsaidmount in position within said envelope to maintain said accurate spacing.

6. 'An electron discharge device comprising an envelopehaving an. insulating portion, a pair of conductive members located on either side. of said insulating portion and each having a. portion thereof extending inside and outside of the envelope, said insulating portion separating said conductive members by a predetermined distance, an electrode mounted on and electrically connected to one ofsaid members, a mount, a second electrode supported onsaid mount and electrically connected to the other of said members, means on said mount-providing with said other of said members accurate spacing of said electrodes in relation to each other, and meansfixing the said mount within said envelope to maintain said spacing.

7. An electron discharge device in accordance with claim 5, wherein said envelope hasan insulating portion, said other member is a metallic disc supported in said insulating portion and connected inside the envelope to said second electrode.

8. An electron discharge device comprising an envelope having insulating portions, a plurality of conductive members mounted on said envelope and separated a fixed distance by said insulating portions, a plurality of electrodes, one of said electrodes supported by and electrically connected with one of said members, a conductive mount supported by and electrically connected to a second ofsaid members, a second electrode supported on said mount and electrically connected thereto,- a third electrode, insulating means supporting said third electrode onsaid mount at a fixed distance from saidsecond electrode, means on said mount providingwith'a third of said members accurate spacing of said mount in regardto said third member, and means electrically connecting said third electrode with said third member, said members extending outside said envelope providin external terminals conneetingv with said electrodes.

9. An electron discharge device in accordance with claim 8, wherein said first electrode is an anode, said-second electrode a'cathode, and said third electrode a grid.

10. An electron discharge device comprising an envelope, a conductive mount supported within said envelope; an e ectrode supported on said mount, means providing a relatively high impedance connection between said electrode and said mount, means coupling said electrode and said mount to -provide a relatively low impedance connectiontherebetween, and av relatively low impedance lead extending'outsi'de of said envelope and connected inside of said envelope to said mount, the value: of; the aforesaid impedances be ing relatively high and low respectively at the highest frequencies at which said device is to be operated.

11. An electron discharge device comprising an envelope, a conductive mount supported within said envelope, an electrode supported on said mount, means providing a relatively high impedance connection between said electrode and said mount, cooperative means on said electrode and said mount capacitatively coupling said electrode and mount to provide a relatively low impedance connection therebetween, and a relatively low impedance lead extending outside of said envelope and connected inside of said envelope to said mount, the value of the aforesaid impedances being relatively high and low respectively at the higher frequencies at which said device is to be operated.

12. An electron discharge device comprising an envelope, a conductive member mounted in said envelope, an electrode, insulating means mounted on said conductive member and supporting said electrode, said electrode being disposed adjacent said conductive member forming a substantial capacity therebetween to provide a low impedance connection between said'eiectrode and said conductive member, and a lead extending through said envelope and connected within said envelope to said conductive member, the value of said impedance being relatively high and low respectively at the higher frequencies at which said device is to be operated.

13. An electron discharge device in accordance with claim 12 and including in addition a high impedance lead interconnecting said conductive member and said electrode, said lead having low heat conductivity.

14. A structural assembly in accordance with claim 1, wherein said mount is conductive, and including means forming a relatively high impedance connection between said mount and said second electrode, means capacitatively coupling said mount and second electrode to provide a relatively low impedance connection therebetween, a relatively low impedance lead extending outside of said envelope and connected within said envelope to said mount, said impedances being relatively high and low respectively at the higher frequencies at which said device is to be operated.

15. In an electron discharge device, an electrode and mount assembly comprising, an electrode, a conductive member, insulating means supported on said conductive member for supporting said electrode adjacent to said conductive member, said electrode and conductive member being disposed adjacent each other to form a substantial capacity therebetween providing a low impedance interconnection, and a lead of relatively high impedance and low thermal conductivity connecting said electrode and said conductive member, the value of said impedances being relatively high and low respectively at the higher frequencies at which said device is to be operated.

16. In an electron discharge device, an electrode and mount assembly comprising, an elec trode, a conductive member, a pair of insulating members supported on opposite sides of said conductive member, said insulating members having openings therein within which said electrode is supported adjacent said conductive memher to form a substantial capacity therebetween to provide a low impedance interconnection, and a lead of relatively high impedance and low thermal conductivity connectingsaid electrode and said conductive member, the value of said impedances being relatively high and low respectively at the higher frequencies at which said device is to be operated.

17. In an electron discharge device, an electrode and mount assembly comprising, a mount including a conductive member and a pair of insulating members supported on opposite sides of said conductive member, said insulating members having openings therein; a cathode supported within said openings adjacent said conductive member to provide a substantial capacity therebetween forming a low impedance interconnection; a lead of relatively high impedance and low thermal conductivity connecting said cathode and said conductive member, the value of said impedances being relatively high and low respectively at the higher frequencies at which said device is to be operated; and a grid supported on said mount by said insulating members at a fixed distance from said cathode.

18. In an electron discharge device, an electrode and mount assembly comprising, a mount including a conductive member and a pair of insulating members supported on opposite sides of said conductive member, said insulating members having openings therein; an indirectly heated cathode supported within said openings adjacent said conductive member to provide a substantial capacity therebetween forming a low impedance interconnection; a lead of relatively high impedance and low thermal conductivity connecting said cathode and said conductive member, the value of said impedances being relatively high and low respectively at the higher frequencies at which said device is to be operated; and a grid supported by said insulating members at a fixed distance from said cathode, said cathode having an electron emissive coating on the face thereof towards said grid.

19. In the method of assembling an electron discharge device, the steps comprising fixedly spacing an electrode and a member within the envelope at an accurate distance from each other, attaching a second electrode to a support, forming an abutment on said support having an accurate position in regard to said second electrode, inserting said electrode-carrying support in said envelope until said abutment abuts said member to thereby accurately space said electrodes from each other, and fixing said support in said position.

JOHN J. GLAUBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,105,506 Ronci Jan. 18, 1938 2,170,663 Painter Aug. 22, 1939 2,185,807 Gabor et al. Jan. 2, 1940 2,195,914 Baier Apr. 2, 1940 2,244,358 Ewald June 3, 1941 2,310,811 Schantl et a1 Feb. 9, 1943 OTHER REFERENCES Ser. No. 386,266, Messner et al. (A. P.C.), pub. May 25, 1943. 

